Dominique Raynaud

The present paper discusses some new findings on the topic of Masaccio's Trinity fresco perspective reconstruction. Some scholars have tried to reduce the fresco's anomalies with the help of photogrammetrical reproductions and computer analysis. On this basis, it has been argued that Masaccio used the normal case of costruzione legittima. It is very likely that Masaccio took the lines of the plane joining the abaci of the capitals as a guide for drawing the vanishing lines of the coffered vault. However, in doing so, he followed an erroneous method of construction disregarded till now. The aberrations thus discovered strongly support the view that Masaccio's Trinity fresco is not a model of linear perspective. The thesis that Masaccio designed the fresco with the help of a ground plan and elevations is dubious, and the search for the distance point is condemned to remain an unending problem.

This paper examines the question of error in perspective from the viewpoint of the painter, not the spectator. This distinction significantly modifies the way in which perspective is approached for one must view it with the eye of the painter or the architect who constructed it. The perspective is therefore judged in terms of the methods used by its creator, which is to say in terms of the goals he set himself and the means at his disposal in order to achieve them. We then explain the "good reasons" the Renaissance painters had to consent to the three main types of error in perspective: "accidental errors" (type I), "ad hoc errors" (type II) and "systematic errors" (type III).

Diffusion of innovations and knowledge is in most cases accounted for by the logistic model. Fieldwork research however constantly report that empirical data utterly deviate from this mathematical function. This chapter scrutinizes network forcing of diffusion process. The departure of empirical data from the logistic function is explained by social network discreteness, heterogeneity and anisotropy. New indices are proposed. Results are illustrated by empirical data from an original study of knowledge diffusion in the medieval academic network.

1. Beaucoup de travaux d’épistémologie contemporaine tentent de spécifier la sociologie par un ensemble de caractères distinctifs dérivés de l’historicité et de l’intentionnalité des sujets humains. 2. Ces caractères doivent être abandonnés, ou réécrits, s’ils rentrent en contradiction avec des avancées scientifiques fondées. 3. Des avancées scientifiques sont fondées si elles ont un caractère de nouveauté, de robustesse et de disciplinarité. 4. La physique statistique exotique parvient à des résultats nouveaux. 5. Elle parvient à des résultats robustes. 6. Elle parvient à des résultats sociologiques. 7. La physique statistique exotique ne tire pas de l’historicité et de l’intentionnalité des sujets humains, une épistémologie spéciale: elle emploie des méthodes scientifiques ordinaires, des lois et des concepts analytiques quantitatifs. 8. Par conséquent, les caractères distinctifs de la sociologie doivent être réécrits sur un mode déflationniste, et critiqués quant à leur déductibilité de l’historicité et de l’intentionnalité.

El cientificismo (scientisme) se ha convertido actualmente en una lacra o un insulto. Nuestra tendencia espontánea es la de apartarnos para evitar ser insultados. Pero es evidente que el cientificismo es atacado a menudo por confundir el conocimiento científico y su uso tecnológico; entre modo de producción de los conocimientos y conocimientos adquiridos, etc. Si se adopta una definición rigurosa del cientificismo como esta: “El cientificismo es la tesis según la cual la mejor manera de conocer el mundo real es conocerlo empleando métodos científicos”, no está claro qué reproches podría sufrir, salvo por parte de los seguidores de la astrología, las flores de Bach o la logorrea posmoderna.

In this chapter, I discuss the "common mind thesis" that social integrates have mind of their own – a thesis which is built on a kind of aggregation paradox named doctrinal paradox. External analysis objects its very name: there is no paradox, but non-commutativity of the function composition involved in the aggregation process (Part I). Internal analysis shows that the doctrinal paradox works only when premises are separable. However premises turn out to be hardly separable in the examples cited in the literature (Part II). As the doctrinal paradox is sometimes considered as an argument of holism, its flaws questions the thesis that groups have minds of their own.

Most studies on scientific sources are conducted using the text parallels method, which consists in presenting two texts opposite each other in order to establish or exclude a correspondence between a «source text» and a «target text.» We have explained elsewhere the limits of this method, especially when (exact) text parallels turn into (approximate) doctrinal parallels, and when the potential sources are numerous. In this context, the search for sources is doomed to failure. In order to operate in this difficult environment, we therefore propose to enhance this method with a special focus on words with low lexical frequency, called «tracers,» in order to better detect their offspring in the target…

This article explores how “partisan thinking” presents itself in the borderlands of science. As science conforms to an objectivity norm, and objectivity is incompatible with the partisan mindset, to discover a latent partisan notion in scientific discourse is to lay bare a contradictio in adjecto. It follows that any partisan elements identified should be placed on the edges of, or even outside, the domain of science. The term “partisan thinking” is a close neighbor to ideology, and so I will briefly review the meaning of each word and explain how they might be distinguished. I will then introduce two examples – the Anthropocene and the French concept of technique – that illustrate the presence of partisan thinking in the realm of science and technology. By two very different routes, each of these ideas carries echoes of the Cold War, and this is clearly of interest to us in seeking to understand how they came to be formed and to pass into popular usage.

Cet article compare les modèles explicatifs en architecturologie et en philosophie analytique de l’action, l’une et l’autre postulant l’existence d’actions finalisées. Cette similitude pose la question de l’identité des échelles de référence et des raisons d’agir. On montre que les échelles sont un sous-ensemble des raisons d’agir. Ce résultat a deux conséquences : 1. Le pouvoir explicatif des raisons d’agir est supérieur à celui des échelles de référence. 2. Raisons d’agir et échelles de référence ont un intérêt pour l’explication ex post du travail de conception. D’où l’orientation de l’« opératoire pur » défendue ici, qui consiste à abandonner les raisons d’agir aux concepteurs pour se concentrer sur la description des opérations de conception par des schèmes d’action. This paper compares the explanatory models in architecturology and analytic philosophy of action that both postulate the existence of willful actions. This likeness questions to what extent architectural reference scales are identical to reasons-to-act. It is shown that the scales are a subset of the reasons-to-act, and this result has two effects : 1. The reasons-to-act have greater explanatory power than the reference scales. 2. Reasons-to-act and reference scales are helpful for the ex post explanation of the design work. Hence the position of « dynamic design » advocated here, which involves abandoning the reasons-to-act to the designers and focusing on the description of design operations through action schemes.

The discovery of the Higgs boson is one of the most significant advances of particle physics in recent years. It led to the award of the Nobel Prize in Physics 2013 to Englert and Higgs for the theory explaining the origin of the particle mass. The Nobel Prize cannot conceal the fact that the results about the new particle have been achieved by the experimental physicists of the ATLAS and CMS collaborations, who are among the largest international collaboration of scientists in the world (2898 and 2932 physicists, respectively). This article is dedicated to the study of the organization and operation of the ATLAS and CMS international collaborations. The disparities between countries, structure of collaborative networks, physicists’ cooperative vs. competitive preferences, and emerging properties of research work in large scientific collaborations are reviewed. Одним из наиболее значительных достижений в области физики элементарных частиц за последние годы стало открытие бозона Хиггса. Это привело к тому, что в 2013 году Нобелевскую премию по физике получили Энглерт и Хиггс за их теорию, объясняющую происхождение массы частиц. Однако Нобелевская премия не может скрыть тот факт, что результаты о новой частице были получены физиками-экспериментаторами коллабораций ATLAS и CMS, которые являются одними из крупнейших международных коллабораций ученых в мире (2898 и 2932 физика соответственно). Эта статья посвящена изучению организации и функционирования международных коллабораций ATLAS и CMS. В работе рассматриваются вопросы неравенства между странами, структуры научных коллаборативных сетей, кооперативных или конкурентных предпочтений физиков, а также новых свойств научно- исследовательской работы; возникающих в крупных научных коллаборациях.

L’article étudie l’inflation du nombre de coauteurs qui touche aujourd’hui plusieurs disciplines comme la physique des particules et les sciences biomédicales. Approfondissant l’exemple des collaborations ATLAS et CMS du CERN qui ont découvert expérimentalement le boson de Higgs en 2012, l’article précise les modalités de signature dans ce champ, étudie les facteurs responsables de l’inflation du nombre de signataires, se demande si cette inflation a provoqué l’apparition de phénomènes inédits, caractérise ces nouveautés, et précise le seuil temporel et numérique auquel elles sont apparues. L’article conclut que l’inflation du nombre d’auteurs en physique des particules est un phénomène émergent (non additif), visible notamment à l’activité normative engagée au sein de ce champ.

This article aims at clarifying sociological definitions with the help of an original tool, the logical table of contingency, which has characteristics in common with both the statistical table of contingency and Carroll’s bilateral diagram. The unclear notion of ghetto is taken as a test-case. Successive tables of contingency are applied to various defining properties and various sociohistorical situations. Cladistic methods are then used to make the relationships between all ghetto-like situations explicit.

This paper examines the hypothesis that early perspective paintings were drawn arithmetically, without vanishing points. The best argument for this hypothesis is that the division of two parallel lines by straight lines intersecting each other at the vanishing point (geometrical method) is equivalent to the division of those parallel lines in proportional parts (arithmetical method). If arithmetical method had been used, then the vanishing points exhibited ex post should be purely fortuitous. But the lack of multiples and submultiples of measurement units, the absence of proportionality ratios, the length of the operating series, and the correspondence of vanishing points to visible loci of the picture offer sound objections for this hypothesis. The use of optics and geometrical method is more probative – though it does not mean that painters were using concepts of linear perspective, which would be an anachronism.

Why are architects faced with a long-standing crisis of legitimacy in democratic countries, even though going to an architect is required by law in most of these countries ? Design work and project management have now turned into a competitive partnership within an egalitarian trend. The crisis of the architectural profession results from the undermining of architects' powers relative to other actors. This fact clearly evokes a Tocquevillian paradigm : in democratic societies, the passion for equality tends to abolish all status differences. This article analyzes the relevance of this paradigm, comparing the unexpected consequences professionals complain about to the features of egalitarism described by Tocqueville. Finally, the author raises the question as to why this egalitarian phenomenon affected architects only from the second half of the XXth century on.

French architects professional crisis is often said to result from the impact of two oil crises on the building trade. Several years of prosperity force to change this diagnosis. In spite of recent building records, French architects still claim to exercise a “disaster profession” that can be no more a sign of economic crisis. The two rival hypotheses, economic crisis vs. crisis of legitimacy, are tested during the ‘Trente Glorieuses’ prosperous period. Architects’ testimonies of these years present all the warning signs of the current crisis. They describe the harmful consequences of design offices’ breaking into the market, and the independence claims of a growing number of actors.

Early modern physiological optics introduced the concept of correspondence through the study of the con- ditions for the fusion of binocular images. The formulation of this concept has traditionally been ascribed to Christiaan Huygens (1667) and to an experiment often attributed to Christoph Scheiner (1619). How- ever, Scheiner’s experiment had already been conceptualized, first by Ptolemy (90–168 AD), then by Ibn al-Haytham (d. after 1040). The extent of the latter’s knowledge of the mechanisms of binocular vision is analyzed. It is explained why Ibn al-Haytham, who addressed this problem as an experimentalist, suc- ceeded in discovering the theoretical horopter (the locus of points in space that yields single vision) and yet failed to recognize that the horizontal line of the horopter could be described as a circular plane around the viewer’s head, credit for which goes to Vieth (1818) and Müller (1826). Through his experiments, Ibn al-Haytham established the notion of corresponding points, explored the cases of homonymous (direct) and heteronymous (crossed) diplopias, and prepared the ground for the discovery of Panum’s fusional area. Finally, the influence of al-Haytham’s pioneering treatise Kitāb al-manāẓir (Book of Optics) on West- ern science is examined, by studying the translations and commentaries that were available in the Latin world.

L’article s’intéresse aux rapports entre problèmes inverses et causalité, et aux procédures concrètes de résolution des problèmes inverses. La comparaison des définitions existantes aboutit à une nouvelle définition des problèmes inverses, intégrative et non causale. De nombreux problèmes inverses étant mal posés, les résoudre implique de les régulariser pour assurer l’existence, l’unicité et la continuité de la solution (en analyse), l’existence et l’unicité (en géométrie). Les procédures concrètes de résolution des problèmes inverses sont étudiées dans le domaine de la synthèse d’image, sur des problèmes projectifs inverses consistant à reconstruire la forme d’un solide à partir de sa représentation perspective. Constatant que les reconstructions 3D s’accompagnent parfois d’un relâchement des exigences méthodologiques, on s’interroge sur les motivations à produire des « solutions » qui ne reposent pas sur des bases scientifiques solides.

This article aims at identifying the sources of fols. 395r and 686r-686v of the Codex Atlanticus. These anonymous folios, inserted in Leonardo da Vinci’s notebooks, do not deal with the duplication of the cube proper, nor do they derive from Giorgio Valla’s De expetendis et fugiendis rebus (1501), as has been claimed. They deal specifically with the extraction of the cube root by geometric methods. The analysis of the sources by the tracer method reveals that these fragments are taken from the Practica geometrie by Leonardo Fibonacci (1220) and, more precisely, from a volgarizzamento that appears in the Praticha d’arismetrica by Benedetto da Firenze (1463). Leonardo could have consulted this text in one of his two Florentine periods, around 1463-1482 or around 1503-1506.

L'étude de la perspective a longtemps souffert d'un a priori dommageable : celui qui consiste à en faire un système culturel « inventé » à la Renaissance, ou, tout au moins, coupé de ses sources médiévales. Depuis une quinzaine d'années, nombre de recherches se sont attachées à montrer ce que devait la perspective aux connaissances du passé, en postulant tour à tour son origine dans l'optique, l'ars metrica, la statique, la géographie ou l'astronomie... Ce livre montre qu'il n'est pas besoin de convoquer l'ensemble de ces sources et défend la thèse d'un courant de diffusion prépondérant, qui va de l'optique élaborée à Oxford au XIIIe siècle, vers les premières représentations picturales italiennes obéissant aux règles de la perspective linéaire. De fait, ce livre délaisse le regard classique que portent l'histoire et la sociologie de l'art sur la perspective, pour s'intéresser essentiellement au réseau des hommes qui ont rendu possible l'avènement de la perspectiva artificialis en diffusant l'optique d'Oxford. Au croisement de l'histoire et de la sociologie des sciences, cette enquête tente de comprendre les raisons politiques et religieuses qui ont déterminé cette transmission culturelle, tout autant, d'ailleurs, que celles qui ont voulu effacer le passé médiéval de la perspective en créant de toutes pièces un « mythe de la perspective ». Ce livre éclaire les rapports entre la science optique et les techniques de représentation, en interrogeant les mobiles des hommes qui ont transmis, et transformé le contenu de la perspective.

“La obra que usted está examinando es el primer estudio de todas las facetas de la tecnología, desde la concepción del artefacto hasta los problemas filosóficos y jurídicos que suscitan el saber y el hacer tecnológicos… Además, Raynaud califica de tóxica para la propia tecnología a la política utilitarista de dar prioridad al ‘desarrollo’ por sobre la investigación básica, ya que todas las innovaciones tecnológicas han utilizado conocimientos básicos… El utilitarismo que pregonan los economistas neoclásicos y los estadistas miopes es el peor peligro que enfrenta la tecnología, la que languidece sin el apoyo de las ciencias básicas. Como decía Guido Beck, mi maestro de física, no han entendido que no puede haber leche de vaca sin vaca”. – Mario Bunge

To students and practitioners of anamorphic art, the name of Jean-François Niceron is more than preeminent; it has become iconic. La Perspective Curieuse was first published in 1638. An augmented version was then translated into Latin by Mersenne in 1646. A newly amended and augmented version was retranslated into French by Roberval in 1652. This book is an English translation of the 1652 text, with reference to the 1638 and 1646 versions. Considering the continued high reputation of the book, the mathematics have been checked for correctness and consistency, and the authors have provided a full commentary, pointing out the most difficult turns of the 17th-century French, the respective contributions of Niceron, Mersenne and Roberval, and explaining Niceron's greatest insights and weaknesses.

Ce livre est un livre d’épistémologie de la sociologie. L’objectif est d’appliquer des méthodes analytiques pour clarifier le vocabulaire, expliciter des relations non-apparentes entre concepts, dégager la portée d’une méthode, ou souligner les incohérences d’un programme de recherche. Les questions épineuses ne sont pas écartéees: Comment clarifier des notions confuses? Peut-on mathématiser les concepts sociologiques? Peut-on pratiquer la sociologie comme on pratique les sciences naturelles? Quelle est la place du déterminisme? Chaque question est examinée à la fois dans sa structure logique et sur des cas concrets. La mathématisation est étudiée sur les mécanismes agrégatifs et sur les modèles de diffusion des innovations. La sociologie expérimentale – généralement méconnue dans la sociologie française – est étudiée sur des programmes de relogement, la diffusion de l’information, ou la genèse de la solidarité sociale. Le livre aborde frontalement la question du déterminisme, du naturalisme, du matérialisme et du scientisme, réputés intenables en sociologie. L’enquête montre que leur rejet résulte généralement de confusions conceptuelles. Une fois écartées, peu d’obstacles s’opposent à leur emploi en sociologie. L’objet de ce livre est la sociologie fondamentale: ensemble des mécanismes qui structurent la production des connaissances sociologiques de base à partir de concepts, programmes ou principes, c’est-à-dire tout ce qui ne relève pas de l’expérience immédiate du terrain et des mondes sociaux.